It is not uncommon that a real-life obsession with a certain fictional character (or the person who plays that character) may carry over onto your dream world. However, if you dream about a fictional character, this can be an omen that something from your unconscious mind is about to emerge or be revealed.
It may also represent memories, images or scenes from your past that were stirred up by reading/watching the movie/book/etc. that featured this fictional character.
To dream of falling or being in love, or becoming physically intimate in any way, with a fictional character represents your understanding about this character and the feelings that he/she generates in you.
Something or someone in your waking life has triggered similar beliefs and feelings.
If you dream about being friends with a fictional character, your dream is telling you that you should have higher self-esteem. You are worth believing in. You need to work on believing that you are a special person.
Also consider the themes of the story, and the journey the character goes on during the story, for more clues to your dream’s meaning.